Marine Interpretation Message
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000
AGPN40 KWNM 200206
MIMPAC

Marine Weather Discussion for N Pacific Ocean
NWS Ocean Prediction Center Washington DC
606 PM PST Sun Nov 19 2017

.FORECAST DISCUSSION...Major features/winds/seas/significant
.weather for the North Pacific N of 30N and E of 150W.

The latest model runs are indicating that the cold front
currently across the pz5 waters will move inland later tonight
and early Mon. Still expect gale force winds up to 40 kt tonight
across portions of the pz5 waters ahead of the front. Another
low will then track west of the pz5 waters Mon night and Tue with
more gales expected for the pz5 and northern pz6 waters. Yet
another low is then expected to track west of the pz5 waters Wed
and Wed night. Farther south, mainly light winds are expected
across most of the southern pz6 waters Mon into Thu. For wind
grids will continue to use the current grids throughout the
forecast period. Current warnings look reasonable and few changes
should be needed on the next offshore waters forecast.

For wave height grids will also continue to use the current grids
throughout the forecast period.

Extratropical storm surge guidance...n/a.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

The ASCAT pass from 18Z shows an area of gale force winds in
advance of the cold front crossing the Washington and Oregon
waters. An altimeter pass from 17Z indicates seas along the
Washington coast near 14 ft at that time. Once this initial
frontal boundary crosses the waters the overall pattern will
become blocked as a high pressure ridge builds over the western
states preventing systems from plowing across the region.
Instead several areas of low pressure will track N-NE, remaining
primarily just W of the waters, although there will still be
periods of 30-35 kt in the southerly flow. The 12Z global models
are in general agreement into day 6 before beginning to diverge
somewhat. The GFS is too fast in bringing the system into the
offshore waters, while the ECMWF is weaker and lags behind. The
Ukmet is actually a good compromise among the models. I populated
the wind grids using the GFS through the entire forecast period,
while slowing down the model by 6 hours on days 6 and 7 to
account for speedy low center.

Seas...For the most part the wave forecast seems reasonable for
both the ENP and WAM throughout the period. I populated the wave
grids using a 50/50 blend of the two models through 00Z Saturday,
then transitioned to the ENP for the remainder of the period
while also shifting the seas 6 hours slower late in the week.

.EXTRATROPICAL STORM SURGE GUIDANCE...n/a.


.WARNINGS...Preliminary.

.PZ5 Washington/Oregon Waters...
.PZZ800...Inner Waters from Cape Flattery to Cape Shoalwater...
     Gale tonight.
     Gale Tuesday.
.PZZ900...Outer Waters from Cape Flattery to Cape Shoalwater...
     Gale Tuesday.
     Gale Possible Wednesday.
.PZZ805...Inner Waters from Cape Shoalwater to Cape Lookout...
     Gale tonight.
     Gale Tuesday.
     Gale Possible Tuesday night.
.PZZ905...Outer Waters from Cape Shoalwater to Cape Lookout...
     Gale tonight.
     Gale Tuesday.
.PZZ810...Inner Waters from Cape Lookout to Florence OR...
     Gale tonight.
     Gale Tuesday.
     Gale Possible Tuesday night.
.PZZ910...Outer Waters from Cape Lookout to Florence OR...
     Gale tonight.
     Gale Tuesday.
.PZZ815...Inner Waters from Florence OR to Point St. George...
     Gale tonight.
     Gale Tuesday.
     Gale Possible Tuesday night.
.PZZ915...Outer Waters from Florence OR to Point St. George...
     Gale tonight.
     Gale Monday night into Tuesday.

.PZ6 California Waters...
.PZZ820...Inner Waters from Point St. George to Point Arena...
     Gale Tuesday.
.PZZ920...Outer Waters from Point St. George to Point Arena...
     Gale Monday night into Tuesday.

$$

.Forecaster Nolt/Shaw. Ocean Prediction Center.



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